Buggy code:
public class MainActivity extends ActionBarActivity implements GoogleApiClient . ConnectionCallbacks , GoogleApiClient . OnConnectionFailedListener { private DateHelper dateHelper = new DateHelper ( ) ; private Button dateButton ; private Button timeButton ; private ToggleButton tb ; public int setAdapterOnView = 0 ; public AutoCompleteTextView fromStation ; public AutoCompleteTextView toStation ; public AutoCompleteTextView viaStation ; public Context mContext ; private ArrayAdapter adaptorAutoComplete ; ArrayList < String > alStations ; String searchString ; public int actAsyncTasks = 0 ; public int setPositionOnView = 0 ; private GoogleApiClient googleApiClient ; private Location lastLocation ; public IOpenTransportRepository repo ; @ Override protected void onCreate ( Bundle savedInstanceState ) { } @ Override protected void onStart ( ) { } @ Override protected void onStop ( ) { } @ Override public boolean onCreateOptionsMenu ( Menu menu ) { } @ Override public boolean onOptionsItemSelected ( MenuItem item ) { } private void showMessage ( String msg ) { } private void changeDirections ( View v ) { } private boolean isEmpty ( AutoCompleteTextView etText ) { } private void refreshDateTime ( ) { } private void setDateButtonSelect ( ) { } private void setTimeButtonSelect ( ) { } private void runSearchConnection ( ) { } public class FetchSearchConnections extends AsyncTask < Void , Void , SearchResultItem > { public ProgressDialog pDia ; public SearchResultItem sItem ; @ Override protected void onPreExecute ( ) { } @ Override protected SearchResultItem doInBackground ( Void ... arg0 ) { } @ Override protected void onPostExecute ( SearchResultItem sItem ) { } } private void runFetchStationList ( CharSequence s , int start , int before , int count ) { } public class FetchStationList extends AsyncTask < Void , Void , Void > { @ Override protected Void doInBackground ( Void ... arg0 ) { } @ Override protected void onPostExecute ( Void aVoid ) { super . onPostExecute ( aVoid ) ; if ( ( actAsyncTasks ) == 1 ) { <START_BUG> adaptorAutoComplete = new ArrayAdapter < String > ( mContext , layout . simple_dropdown_item_1line , alStations ) ; <END_BUG> if ( ( setAdapterOnView ) == 1 ) { fromStation . setAdapter ( adaptorAutoComplete ) ; } else if ( ( setAdapterOnView ) == 2 ) { toStation . setAdapter ( adaptorAutoComplete ) ; } else if ( ( setAdapterOnView ) == 3 ) { viaStation . setAdapter ( adaptorAutoComplete ) ; } adaptorAutoComplete . notifyDataSetChanged ( ) ; ( actAsyncTasks ) -- ; } else { ( actAsyncTasks ) -- ; } } } private void SetGpsPosition ( ) { } public class FetchStationLocation extends AsyncTask < Double , Void , String > { public ProgressDialog pDia1 ; public SearchResultItem sItem ; @ Override protected void onPreExecute ( ) { } @ Override protected String doInBackground ( Double ... arg0 ) { } @ Override protected void onPostExecute ( String result ) { } } @ Override public void onConnected ( Bundle bundle ) { } @ Override public void onConnectionSuspended ( int i ) { } @ Override public void onConnectionFailed ( ConnectionResult connectionResult ) { } public void hideSoftKeyboard ( View view ) { } @ Override public boolean dispatchTouchEvent ( MotionEvent event ) { } }

Fix:
adaptorAutoComplete = new ArrayAdapter < String > ( mContext , layout . simple_dropdown_item_1line , new ArrayList < String > ( alStations ) ) ;